In cases where a pipe system for transporting gas, either natural gas or gas mixed with other hydrocarbons is unavailable, it is difficult to carry out an efficient use. In such cases, continious combustion of the gas is impossible, it cannot be used on the spot, e.g. at an offshore platform, or transported to the customer through a pipeline.
One possibility in such situations is to re-inject the gas to the reservoir to promote the oil production. The development of certain isolated gas fields, e.g. offshore, is economically impossible without permitting utilization on the spot or transportation through a pipeline.
It is also possible to carry out treatment on the spot by producing liquidous natural gas, methanol and ammonia. However, these three possibilities require extensive treatment of the natural gas and/or another gaseous product and requires equipment that is comprehensive and on a scale that is not suited for offshore production.
U.S. Pat. No. 3,514,274 discloses a method for solving the transportation problem, in which natural gas is converted to hydrates and transported/stored in propane or other C.sub.4 -C.sub.5 hydrocarbons. In this case, the propane is used as a recyclable energy carrier, and the natural gas hydrate is dehydrated at the delivery point and convened to pure natural gas simultaneously with converting the propane to propane hydrate. Then, the propane hydrate can be used again for the production of natural gas hydrate, in which compressed and cooled natural gas is contacted with propane hydrate in a reactor, thus converting propane hydrate to propane carrier liquid and natural gas to natural gas hydrate. However, this method has the disadvantage that dead weight, i.e. propane, must be transported all the time. Moreover, the transportation and storage temperature must be as low as -22.degree. C. to avoid evaporation of the propane carrier liquid.
NO 149976, patent publication laid open to public inspection, discloses a method for transporting natural gas in a boat submerged in water. Natural gas and fresh water is separately fed into a submerged marine ship and combined to form gas hydrate, whereupon the hydrate is kept stable during transportation by means of the hydrostatic pressure and the relatively low temperature of the sea water. However, this method requires that the pressure and the temperature is maintained throughout transportation, and requires use of specially contructed submarines that have a low loading capacity compared with surface ships. Moreover, problems may arise if the shipping terminals are located in an area with shallow and relatively warm water. Moreover, the method disclosed in this patent publication is naturally limited to marine transportation only, and will not contribute to a solution where only pipeline transportation or transportation as LNG is available.
In other cases, one faces gas emission such as polluting by-products from industrial processes where a removal of the gas is desired but purification or destrucion on the spot is impossible.